North American P-51 Mustang in the context of "Rolls-Royce Merlin"

Brigadier General Charles Elwood Yeager (/ˈjeɪɡər/ YAY-gər, February 13, 1923 – December 7, 2020) was a United States Air Force officer, flying ace, and record-setting test pilot who in October 1947 became the first pilot in history confirmed to have exceeded the speed of sound in level flight.

Yeager was raised in Hamlin, West Virginia. His career began in World War II as a private in the United States Army, assigned to the Army Air Forces in 1941. After serving as an aircraft mechanic, in September 1942, he entered enlisted pilot training and upon graduation was promoted to the rank of flight officer (the World War II Army Air Force version of the Army's warrant officer), later achieving most of his aerial victories as a P-51 Mustang fighter pilot on the Western Front, where he was credited with shooting down 11.5 enemy aircraft. The half credit is from a second pilot assisting him in a single shootdown. On October 12, 1944, he attained "ace in a day" status, shooting down five enemy aircraft in one mission.

Over twenty variants of the North American P-51 Mustang fighter were produced from 1940, when it first flew, to after World War II, some of which were employed also in the Korean War and in several other conflicts.

The Lockheed P-38 Lightning is an American single-seat, twin-engined fighter aircraft that was used during World War II. Developed for the United States Army Air Corps (USAAC) by the Lockheed Corporation, the P-38 incorporated a distinctive twin-boom design with a central nacelle containing the cockpit and armament. Along with its use as a general fighter, the P-38 was used in various aerial combat roles, including as a highly effective fighter-bomber, a night fighter, and a long-range escort fighter when equipped with drop tanks. The P-38 was also used as a bomber-pathfinder, guiding streams of medium and heavy bombers, or even other P-38s equipped with bombs, to their targets. Some 1,200 Lightnings, about 1 of every 9, were assigned to aerial reconnaissance, with cameras replacing weapons to become the F-4 or F-5 model; in this role it was one of the most prolific recon airplanes in the war. Although it was not designated a heavy fighter or a bomber destroyer by the USAAC, the P-38 filled those roles and more; unlike German heavy fighters crewed by two or three airmen, the P-38, with its lone pilot, was nimble enough to compete with single-engined fighters.

The P-38 was used most successfully in the Pacific and the China-Burma-India theaters of operations as the aircraft of America's top aces, Richard Bong (40 victories), Thomas McGuire (38 victories), and Charles H. MacDonald (27 victories). In the South West Pacific theater, the P-38 was the primary long-range fighter of United States Army Air Forces until the introduction of large numbers of P-51D Mustangs toward the end of the war. Unusually for an early-war fighter design, both engines were supplemented by turbosuperchargers, making it one of the earliest Allied fighters capable of performing well at high altitudes. The turbosuperchargers also muffled the exhaust, making the P-38's operation relatively quiet. The Lightning was extremely forgiving in flight and could be mishandled without incident in many ways, but the initial rate of roll in early versions was low relative to other contemporary fighters; this was addressed in later variants with the introduction of hydraulically boosted ailerons. The smaller and more streamlined P-51 was significantly faster in a dive, which led to the P-51 replacing the P-38 in most European fighter groups by mid-1944. The P-38 was the only American fighter aircraft in large-scale production throughout American involvement in the war, from the Attack on Pearl Harbor to Victory over Japan Day.

North American Aviation (NAA) was a major American aerospace manufacturer that designed and built several notable aircraft and spacecraft. Its products included the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F-86 Sabre jet fighter, the X-15 rocket plane, the XB-70 bomber, the B-1 Lancer, the Apollo command and service module, the second stage of the Saturn V rocket, and the Space Shuttle orbiter.

Through a series of mergers and sales, North American Aviation became part of North American Rockwell, which later became Rockwell International, and is now part of Boeing.

The Curtiss P-40 Warhawk is an American single-engined, single-seat, all-metal fighter-bomber that first flew in 1938. The P-40 design was a modification of the previous Curtiss P-36 Hawk which reduced development time and enabled a rapid entry into production and operational service. The Warhawk was used by most Allied powers during World War II, and remained in frontline service until the end of the war. It was the third most-produced American fighter of World War II, after the North American P-51 Mustang and Republic P-47 Thunderbolt; by November 1944, when production of the P-40 ceased, 13,738 had been built, all at Curtiss-Wright Corporation's main production facilities in Buffalo, New York.

P-40 Warhawk was the name the United States Army Air Corps gave the plane, and after June 1941, the USAAFadopted the name for all models, making it the official name in the US for all P-40s. The British Commonwealth and Soviet air forces used the name Tomahawk for models equivalent to the original P-40, P-40B, and P-40C, and the name Kittyhawk for models equivalent to the P-40D and all later variants. P-40s first saw combat with the British Commonwealth squadrons of the Desert Air Force in the Middle East and North African campaigns, during June 1941. No. 112 Squadron Royal Air Force, was among the first to operate Tomahawks in North Africa and the unit was the first Allied military aviation unit to feature the "shark mouth" logo, copying similar markings on some Luftwaffe Messerschmitt Bf 110 twin-engine fighters.

The North American Mustang Mk.X, also known as the "Rolls-Royce Mustang" or Mustang X, was an experimental variant of the North American Mustang I, (factory designation Model NA-73) where the Allison engine was replaced by a Rolls Royce Merlin. The improvements in performance led to the adoption of the Merlin, in the form of the licence-built Packard V-1650 version of the Merlin, in following production of the P-51 Mustang.

The Mustang, had been designed and developed by North American Aviation in 1940 to a requirement by the British Purchasing Commission for fighters to equip the Royal Air Force. However while the airframe was sound, the engine did not perform well at the high altitudes characteristic of air to air combat over Europe. Rolls Royce took up a recommendation that the Mustang be tested with a Merlin engine and five aircraft were converted. The aircraft were tested by the British and then the US Army Air Forces.

The Packard V-1650 Merlin is a version of the Rolls-Royce Merlin aircraft engine, produced under license in the United States by the Packard Motor Car Company. The engine was licensed to expand production of the Rolls-Royce Merlin for British use. The engine also filled a gap in the U.S. at a time when similarly powered American-made engines were not available.

The first V-1650s, with a one-stage supercharger, equivalent to the Merlin XX, were used in the P-40F Kittyhawk fighter and in Canadian-built Hawker Hurricanes. Later versions based on the Merlin 60 series included a more advanced two-stage supercharger for improved performance at high altitudes. It found its most notable application in the North American P-51 Mustang fighter, improving the aircraft's performance making them capable of escorting Allied heavy bombers to Germany or Japan and back.

The Defence of the Reich (German: Reichsverteidigung) was the strategic defensive aerial campaign fought by the Luftwaffe of Nazi Germany over German-occupied Europe and Germany during World War II against the Allied strategic bombing campaign. Its aim was to prevent the destruction of German civilians, military and civil industries by the Western Allies. The day and night air battles over Germany during the war involved thousands of aircraft, units and aerial engagements to counter the Allied bombing campaigns. The campaign was one of the longest in the history of aerial warfare and with the Battle of the Atlantic and the Allied naval blockade of Germany was the longest of the war. The Luftwaffe fighter force defended the airspace of German-occupied Europe against attack, first by the RAF Bomber Command and then against the RAF and United States Army Air Forces (USAAF) in the Combined Bomber Offensive.

In the early years, the Luftwaffe was able to inflict a string of defeats on Allied strategic air forces. In 1939, Bomber Command was forced to operate at night, due to the extent of losses of unescorted bombers flying in daylight. In 1943, the USAAF suffered several reverses in daylight and called off the offensive over Germany in October limiting their attacks to western Europe as they built up their force. During the war the British built up their bomber force, introducing better aircraft with navigational aids and tactics such as the bomber stream that enabled them to mount larger and larger attacks while remaining within an acceptable loss rate. In 1944 the USAAF introduced metal drop tanks for all American fighters including the newly arrived North American P-51D Mustang variant, which allowed fighter aircraft to escort USAAF bombers all the way to and from their targets. With a change of focus on destroying the German day fighter force, by the spring of 1944 the Eighth Air Force had achieved air supremacy over Western Europe, which was essential for the Allies so they could carry out the invasion of France. The strategic campaign against Germany eased as the Allies' Transport Plan focused their resources on isolating northern France in preparation for the invasion.